Allo-anti-M: Detection peaks around 2 years of age, but may be attenuated by red blood cell transfusion.

BACKGROUND: Anti-M is frequently observed as a naturally occurring antibody of little clinical significance. Naturally occurring anti-M is often found in children although the specific triggers of production, persistence, and evanescence of anti-M have yet to be elucidated. METHODS: In a retrospective, multicenter, nationwide cohort survey conducted from 2001 to 2015, alloantibody screening was performed before and after transfusion in 18,944 recipients younger than 20 years. Recipients were categorized into six cohorts based on their age at transfusion; within and among these cohorts, allo-anti-M was analyzed in regard to its production, persistence, and evanescence. RESULTS: In 44 patients, anti-M detected before and/or after transfusion was an age-related phenomenon, with a median age of 2 years and an interquartile range of 1-3 years; anti-M was most frequently detected in a cohort of children 1 to <5 years (0.77%, 31 of 4035). At least five patients were presumed to have concurrent infections. Among 1575 adolescents/young adults (15 to <20 years), no anti-M was detected. Of 29 patients with anti-M prior to transfusion, the antibody fell to undetectable levels in 17 recipients (89.5%, of whom at least 13 received only M-negative red cells) after anywhere from 5 days to 5.8 years; anti-M persisted in 2, and was not tested in 10. Only 15 recipients (0.08%) produced new anti-M after transfusion. CONCLUSION: Naturally occurring anti-M is a phenomenon of younger ages, predominantly between 1 and 3 years. After transfusion, it often falls to undetectable levels.

A newly devised flow cytometric antibody binding assay helps evaluation of dithiothreitol treatment for the inactivation of CD38 on red blood cells.

BACKGROUND AND OBJECTIVES: Anti-CD38 monoclonal antibodies, including daratumumab and isatuximab, often interfere with pretransfusion testing. Dithiothreitol (DTT) treatment of red blood cells (RBCs) negates this interference. However, the optimum DTT concentration and treatment time have not been well defined. Here, we quantified CD38 on RBCs before and after DTT treatment using a flow cytometric antibody binding assay (FABA) to specify the optimum conditions for CD38 inactivation. MATERIALS AND METHODS: For FABA, untreated or DTT-treated RBCs were incubated with fluorescein isothiocyanate-labelled anti-CD38 antibody, in the presence or absence of 100-fold or more excess of unlabelled anti-CD38 antibody, and then analysed by flow cytometry (FCM). Dissociation of CD38-positive and control histograms was determined from the D-value using the Kolmogorov-Smirnov test. The results from FABA were compared with those from conventional FCM, indirect antiglobulin test (IAT) and Western blotting. RESULTS: The results from FABA were more consistent than those from conventional FCM. The D-value was found to be reliable in the analysis of difference between CD38 before and after DTT treatment. Our data showed that 0·0075 mol/l DTT for 30 min is sufficient to inactivate CD38 on RBCs. These results were stable and consistent with the findings from IAT. CONCLUSION: Flow cytometric antibody binding assay is an objective way of evaluating the efficacy of DTT treatment for CD38 on RBCs. This approach allows the detection of a small number of cell surface antigens and will be useful for assessing the various chemical treatments to denature RBC antigens.

Transfusion-associated circulatory overload and high blood pressure: A multicentre retrospective study in Japan.

BACKGROUND: Transfusion-associated circulatory overload (TACO) is an adverse reaction associated with a high risk of mortality. The actual incidence of TACO and hypertension associated with transfusion in Japan is unknown. METHODS: A multicentre retrospective observational study was conducted across 23 institutions during the 1-year period of 2016. Patients were included if they developed TACO or their blood pressure (either systolic or diastolic) increased by at least 30 mmHg during the transfusion. TACO was confirmed by the primary physicians and transfusion medicine teams and recorded in the data on passive surveillance, and additional data were extracted from electronic medical records. RESULTS: In our patient cohort of 31 384 patients who underwent transfusion, the incidence of TACO and hypertension was 0·03% and 0·2%, respectively. However, 43% of the participating institutions didn't report any cases. When comparing risk factors between the TACO and hypertension groups, there were significant differences in comorbidities, such as abnormal findings on chest x-ray. Significant differences between the two groups were observed post-transfusion pulse rate, body temperature and oxygen saturation (P < 0·01). In the group of patients with hypertension, the level of BNP increased significantly after transfusion in 45% (5/11) of the patients. We identified 4 patients in the hypertension group who met the new ISBT's TACO criteria. CONCLUSION: Our study suggests that more attention should be given to TACO in Japan, particularly in terms of improving surveillance systems. For the early diagnosis of TACO, it is crucial to carefully monitor vital signs including blood pressure.

Predictors of early death, serious hemorrhage, and differentiation syndrome in Japanese patients with acute promyelocytic leukemia.

Significant advancements have been achieved with regard to the outcomes of acute promyelocytic leukemia (APL) patients through the introduction of all-trans retinoic acid; however, early hemorrhagic death and differentiation syndrome remain the major causes of remission induction failure in patients with APL. To investigate early death, serious hemorrhage, and differentiation syndrome during remission induction therapy in terms of incidence, risk factors, influence on outcomes, and prophylactic effects of several new anticoagulants, the results of 344 patients enrolled in the Acute Promyelocytic Leukemia 204 study conducted by the Japan Adult Leukemia Study Group were analyzed. Early death was observed in 16 patients (4.7%), of whom 14 had serious hemorrhage and 2 had differentiation syndrome. Serious hemorrhage and differentiation syndrome of grade 2 or higher were observed in 21 and 54 patients, respectively. Patients who achieved complete remission had a 7-year disease-free survival of 84.8% if they did not experience serious hemorrhage and 40.0% if they experienced serious hemorrhage during remission induction therapy (P = 0.001). Risk factor analyses showed that higher white blood cell count was associated with early death, higher white blood cell count and lower platelet count with serious hemorrhage, and leukocytosis during induction therapy and higher body surface area with differentiation syndrome. In conclusion, these results indicate that patients with such high-risk features may benefit from more intensive supportive care. The hemorrhagic risk was not relieved by the introduction of new anticoagulants. Further studies are required to establish the predictive impact of body surface area on differentiation syndrome. This trial is registered with UMIN-CTR as C000000154 on September 13, 2005.

A Japanese multi-institutional collaborative study of antigen-positive red blood cell (RBC) transfusions in patients with corresponding RBC antibodies.

BACKGROUND AND OBJECTIVES: It is sometimes difficult to obtain antigen-negative red blood cells (RBCs) for patients with antibodies against RBCs. However, the frequency and severity of the adverse reactions have not been well elucidated. Here, we conducted a multi-institutional collaborative study to clarify the background, frequency and clinical significance of antigen-positive RBC transfusions to patients with the respective antibodies. MATERIALS AND METHODS: The survey included the background of patients, antigens on RBCs transfused, total amount of antigen-positive RBCs transfused, results from antibody screen and direct antiglobulin tests, specificity of antibodies, adverse reactions and efficacies. All antibodies were surveyed regardless of their clinical significance. RESULTS: In all, 826 cases containing 878 antibodies were registered from 45 institutions. The main reasons for antigen-positive RBC transfusions included 'negative by indirect antiglobulin test' (39%) and 'detection of warm autoantibodies' (25%). In 23 cases (3% of total), some adverse reactions were observed after antigen-positive RBC transfusion, and 25 antibodies (9 of 119 clinically significant and 16 of 646 insignificant antibodies) were detected. Non-specific warm autoantibodies were detected in 9 cases, anti-E in 5 cases, 2 cases each of anti-Lea , anti-Jra or cold alloantibodies, and 1 case each of anti-Dib , anti-Leb or anti-P1. Other antibodies were detected in 2 further cases. Five (22%) of these 23 cases, who had anti-E (3 cases) or anti-Jra (2 cases), experienced clinically apparent haemolysis. CONCLUSIONS: Adverse reactions, especially haemolysis, were more frequently observed in cases with clinically significant antibodies than those with clinically insignificant antibodies (P < 0·001).

Erythrocyte Alloimmunity and Genetic Variance: Results from the Collaborative Study of Alloimmunity to Antigen Diversity in Asian Populations (All ADP).

As an East-Asian international study, we evaluated erythrocyte alloimmunity by gender and history of transfusion or pregnancy. In total, data from more than 1,826,000 patients were analyzed, from whom 26,170 irregular erythrocyte antibodies were detected in 22,653 cases. Antibody frequencies in these cases were as follows: anti-E, 26.8%; anti-Lea, 20.0%; anti-P1, 7.1%; anti-M, 6.4%; anti-Mia, 5.6%; anti-c + E, 5.6%; anti-Leb, 4.6%; anti-D, 2.8%; anti-Fyb, 2.6%; anti-Lea+Leb, 2.5%; anti-Dia, 2.0%; and others. For pregnant patients, anti-D (12.7%) was statistically more frequent. For transfused patients, anti-E (37.3%), anti-c + E (9.5%), anti-C + e (3.3%) and anti-Jka (3.1%) were significantly more frequent.

Clinical significance of ASXL2 and ZBTB7A mutations and C-terminally truncated RUNX1-RUNX1T1 expression in AML patients with t(8;21) enrolled in the JALSG AML201 study.

We analyzed the clinical significance and genetic features of ASXL2 and ZBTB7A mutations, and the alternatively spliced isoform of the RUNX1-RUNX1T1 transcript, which is also called AML1-ETO9a (AE9a), in Japanese CBF-AML patients enrolled in the JALSG AML201 study. ASXL2 and ZBTB7A genes were sequenced using bone marrow samples of 41 AML patients with t(8;21) and 14 with inv(16). The relative expression levels of AE9a were quantified using the real-time PCR assay in 23 AML patients with t(8;21). We identified ASXL2 (34.1%) and ZBTB7A (9.8%) mutations in only AML patients with t(8;21). ASXL2-mutated patients had a significantly higher WBC count at diagnosis (P = 0.04) and a lower frequency of sex chromosome loss than wild-type patients (33 vs. 76%, respectively, P = 0.01). KIT mutations were the most frequently accompanied with both ASXL2 (36%) and ZBTB7A (75%) mutations. Neither ASXL2 nor ZBTB7A mutations had an impact on overall or event-free survival. Patients harboring cohesin complex gene mutations expressed significantly higher levels of AE9a than unmutated patients (P = 0.03). In conclusion, ASXL2 and ZBTB7A mutations were frequently identified in Japanese AML patients with t(8;21), but not in those with inv(16). Further analysis is required to clarify the detailed biological mechanism of AE9a regulation of the cohesin complex.

Released washed platelet concentrates are effective and safe in patients with a history of transfusion reactions.

BACKGROUND: Plasma removal by washing is an effective approach to prevent transfusion reactions by platelet concentrates (PCs). Recently, washed PCs were released by the Japanese Red Cross Society (JRCS). MATERIALS AND METHODS: This retrospective multicenter study evaluated the efficacy and safety of released washed PCs (RWPCs) between September 2016 and January 2017 in Japan. The RWPCs were prepared by washing leukoreduced apheresis PCs with the platelet additive solution, BRS-A, using automated cell processors. RESULTS: Clinical data were obtained from 91 patients and 1210 RWPC transfusions at 50 institutions. The median number of RWPC transfusions per patient was 8 (range, 1-91). RWPCs were used in 94.5% of the patients with a history of recurrent or severe transfusion reactions for preventing such reactions. Responses of RWPCs were evaluated as complete response (91.6%), partial response (8.2%), no-change (0.2%), and progression (0%) and overall response was equal across subgroups divided by patients' profiles. The median corrected count increment (CCI) at 1 and 24 h post-transfusion were 13.5 (range, 1.9-35.4) × 109/L and 3.5 (range, -13 to 53.6) × 109/L, respectively, and median CCI at 24 h was 5.5 (range, -13 to 53.6) × 109/L in patients without risk factors associated with platelet transfusion refractoriness. Transfusion reactions to RWPCs were observed in only nine transfusions (0.7%), all of which were mild allergic reactions. CONCLUSION: This study demonstrated that RWPCs were effective and safe in patients with a history of transfusion reactions. Further prospective studies on efficacy together with cost-benefit analysis in RWPCs are needed.

A national survey of premedication for transfusion reactions in Japan.

BACKGROUND: Premedication before transfusion is commonly administered in clinical practice despite a lack of evidence for its efficacy. The aim of this study was to clarify the status of premedication and evaluate expert opinions regarding its use in Japanese medical institutions. METHOD: Between May and July 2016, we conducted a questionnaire survey on premedication before transfusion in 252 medical institutes that were certified by an academic society or employed transfusion experts. RESULTS: A total of 141 institutes (54.2%) responded, and hematologists (n=113) comprised the most frequent respondents. The purpose of premedication was to prevent urticaria, pruritus, and fever, and washed blood products were used for anaphylactic shock or refractory transfusion reactions before. Drugs for premedication were intravenously administered either just before or 30min before transfusion. Both inpatients and outpatients were premedicated in a similar manner, and institutional guidelines were not established. More than half of the experts recognized premedication as efficient and necessary, and premedication for previous transfusion reactions was frequently implemented, particularly for platelet transfusion or in patients with hematological diseases. Some institutions administered one or more drugs for premedication from the first transfusion. Antihistamines and hydrocortisone were the most frequently used as premedication. CONCLUSION: Our study reports the current status of premedication for transfusion in Japan. Antihistamines and hydrocortisone were most commonly used for premedication despite a lack of evidence of their use. These findings may help clarify the indications for premedication and the use of washed blood products.

Involvement of transfusion unit staff in the informed consent process.

BACKGROUND AND OBJECTIVES: Obtaining informed consent (IC) for a blood transfusion is an absolute requirement. In this study, we compared the depth of understanding of blood transfusion among patients with or without an explanation by the transfusion unit staff and evaluated the usefulness of this intervention in obtaining IC. MATERIALS AND METHODS: Expert staff from the transfusion unit started to provide patients with a basic explanation of blood transfusion (intervention group, n = 129). The efficacy of this strategy was assessed by comparison with explanation given by the primary doctors only (conventional group, n = 31). We performed a questionnaire survey to analyze the length of time spent providing information of blood transfusion and the depth of understanding of blood transfusion in the two groups. RESULTS: The median time in providing information in the conventional and intervention groups was 6 and 20 minutes, respectively (P < 0.0001). Patients in the intervention group had a better understanding of several key points on blood transfusion than those in the conventional group. CONCLUSION: Our results show that expert staff from the transfusion unit should be involved in obtaining IC for a blood transfusion. Patients who were provided information by transfusion unit staff were more likely to have a better understanding of the risks and benefits of transfusion.

Phase 2 study of arsenic trioxide followed by autologous hematopoietic cell transplantation for relapsed acute promyelocytic leukemia.

The optimal treatments for relapsed acute promyelocytic leukemia (APL) remain equivocal. We conducted a phase 2 study to evaluate the efficacy and feasibility of a sequential treatment consisting of induction and consolidation with arsenic trioxide (ATO), peripheral blood stem cell (PBSC) harvest after high-dose cytarabine chemotherapy, and autologous hematopoietic cell transplantation (HCT). Between 2005 and 2009, 35 patients (26 with hematologic and 9 with molecular relapse) were enrolled. Induction therapy resulted in complete remission in 81% of those with hematologic relapse, and most patients became negative for PML-RARα after the first ATO consolidation course, but 4 remained positive. Administration of the second ATO consolidation course further decreased the transcript levels in 3 patients. In total, 25 patients proceeded to PBSC harvest, all of whom successfully achieved the target CD34+ cell doses, and 23 underwent autologous HCT with PML-RARα-negative PBSC graft. Posttransplant relapse occurred in 3 patients, and there was no transplant-related mortality. With a median follow-up of 4.9 years, the 5-year event-free and overall survival rates were 65% and 77%, respectively. These findings demonstrate the outstanding efficacy and feasibility of the sequential treatment featuring ATO and autologous HCT for relapsed APL. This study was registered at http://www.umin.ac.jp/ctr/ as #C000000302.

Evaluation of the in-hospital hemovigilance by introduction of the information technology-based system.

BACKGROUND: Hemovigilance is an important aspect of transfusion medicine. However, the frequency of the adverse reactions often varies using different reporters. Recently, we have employed a new information technology (IT)-based in-hospital hemovigilance system. Here, we evaluated changes in practice after implementation of an IT-based reporting system. STUDY DESIGN AND METHODS: We compared the rate of frequency and details of blood transfusion-related adverse reactions 3 years before and after introduction of the IT-based reporting system. Contents and severity of the adverse reactions were reported in a paper-based reporting system, but input by selecting items in an IT-based reporting system. The details of adverse reactions are immediately sent to the blood transfusion unit online. RESULTS: After we introduced the IT-based reporting system, the reported rate of transfusion-related adverse reactions increased approximately 10-fold from 0.20% to 2.18% (p < 0.001), and frequencies of urticaria, pruritus, rash, fever (p < 0.001), hypertension (p = 0.001), tachycardia (p = 0.003), and nausea and vomiting (p = 0.010) increased significantly. Although there was no error report in the paper-based reporting, incorrect reports were observed in 90 cases (0.52%) in the IT-based reporting (p < 0.001). CONCLUSION: The advantages of IT-based reporting were: 1) a significant increase in the frequency of adverse reaction reporting and 2) a significant decrease in underreporting, although the true frequency has yet to be clarified. The disadvantage of the IT-based reporting was an increased incidence of incorrect inputs, all of which was unnoticed by the reporters. Our results showed several important points in need of monitoring after introduction of an IT-based reporting system.

Expression of CD56 is an unfavorable prognostic factor for acute promyelocytic leukemia with higher initial white blood cell counts.

Expression of CD56 has recently been introduced as one of the adverse prognostic factors in acute promyelocytic leukemia (APL). However, the clinical significance of CD56 antigen in APL has not been well elucidated. We assessed the clinical significance of CD56 antigen in 239 APL patients prospectively treated with all-trans retinoic acid and chemotherapy according to the Japan Adult Leukemia Study Group APL97 protocol. All patients were prospectively treated by the Japan Adult Leukemia Study Group APL97 protocol. The median follow-up period was 8.5 years. Positive CD56 expression was found in 23 APL patients (9.6%). Expression of CD56 was significantly associated with lower platelet count (P = 0.04), severe disseminated intravascular coagulation (P = 0.04), and coexpression of CD2 (P = 0.03), CD7 (P = 0.04), CD34 (P < 0.01) and/or human leukocyte antigen-DR (P < 0.01). Complete remission rate and overall survival were not different between the two groups. However, cumulative incidence of relapse and event-free survival (EFS) showed an inferior trend in CD56(+) APL (P = 0.08 and P = 0.08, respectively). Among patients with initial white blood cell counts of 3.0 × 10(9)/L or more, EFS and cumulative incidence of relapse in CD56(+) APL were significantly worse (30.8% vs 63.6%, P = 0.008, and 53.8% vs 28.9%, P = 0.03, respectively), and in multivariate analysis, CD56 expression was an unfavorable prognostic factor for EFS (P = 0.04). In conclusion, for APL with higher initial white blood cell counts, CD56 expression should be regarded as an unfavorable prognostic factor.

[Management directed at preventing misidentifications by introduction of the computed identification system and blood sampling by the transfusion unit; aim for good partnership between a transfusion unit and bedsides].

The initial step of blood transfusion therapy is blood type grouping. ABO-mismatch blood transfusion results in serious adverse effects. Several incidents in the process of blood sampling had been experienced in our hospital since 2006 to 2008. Therefore, we have introduced the computed identification system, and the transfusion unit has taken a part of blood sampling. Just after we introduced it in July 2010, only 7% of the doctors and the nurses used the system in blood sampling. Repeated training programs for doctors and nurses on blood sampling procedure improved the utilization to 95%. We realized the importance of our management in face of its introduction. We have to make continuous efforts on the safety of transfusion therapy, because new type of incidents can appear.

Role of hematopoietic stem cell transplantation for relapsed acute promyelocytic leukemia: a retrospective analysis of JALSG-APL97.

For patients with relapsed acute promyelocytic leukemia (APL), all-trans retinoic acid-based salvage regimens can achieve second complete remission (CR2), but the optimal post-remission strategy for APL patients after CR2 remains unclear. Hematopoietic stem cell transplantation (HSCT) during CR2 might be effective, but data on the role of HSCT for APL patients after CR2 are limited in Japan. We retrospectively analyzed outcomes for 57 relapsed APL patients who achieved CR2 in the JALSG APL97 study. Of those, six received autologous (auto)-HSCT, 21 received allogeneic (allo)-HSCT, and 30 received various regimens other than HSCT. The 5-year event-free survival (EFS) rate, overall survival (OS) rate and cumulative incidence of relapse (CIR) were 50.7%, 77.4% and 51.0% in the non-HSCT group, 41.7%, 83.3% and 58.3% in the auto-HSCT group and 71.1%, 76.2% and 9.8% in the allo-HSCT group, respectively. Both the EFS rate and CIR were significantly better in the allo-HSCT group than in other groups. Allo-HSCT appears effective in APL patients in CR2, with a low relapse rate beyond a relatively early transplantation-related mortality (19%). Among older patients (age ≥40 years), the 5-year OS was significantly better in the non-HSCT group than in the HSCT group (78.0% vs 40.5%; P = 0.04). Further prospective studies with larger patient numbers are required to confirm the impact of HSCT alone and in combination with arsenic trioxide on outcomes for patients with APL in CR2.

Long-term outcome and prognostic factors of elderly patients with acute promyelocytic leukemia.

Studies focused on elderly acute promyelocytic leukemia (APL) are relatively limited. To evaluate prognostic impact in elderly APL, we compared the long-term outcome of elderly APL patients (60-70 years) with younger patients (15-59 years) treated with all-trans retinoic acid combined with anthracycline and cytarabine in the Japan Adult Leukemia Study Group (JALSG) APL97 study. Of 283 evaluable patients, 46 (16.3%) were elderly who had more frequent lower platelet (P = 0.04), lower albumin (P = 0.006) and performance status 3 (P = 0.02), higher induction death rate due to differentiation syndrome (P = 0.03), and non-relapse mortality (NRM) during consolidation therapy (P = 0.001). Overall survival was significantly inferior in elderly patients (P = 0.005), but disease-free survival and cumulative incidence of relapse were not. Better therapeutic approaches should be considered to reduce NRM during induction and consolidation therapy in elderly APL. This study was registered at http://www.umin.ac.jp/ctrj/ under C000000206.

Phase I trial of gemtuzumab ozogamicin in intensive combination chemotherapy for relapsed or refractory adult acute myeloid leukemia (AML): Japan Adult Leukemia Study Group (JALSG)-AML206 study.

In order to investigate better molecular-target therapy for acute myeloid leukemia (AML), we conducted a phase I trial of a combination of gemtuzumab ozogamicin (GO) with conventional chemotherapy. Between January 2007 and December 2009, a total of 19 adult Japanese patients with relapsed or refractory CD33-positive AML (excluding acute promyelocytic leukemia) were enrolled. All registered patients received a standard dose of cytarabine (Ara-C) (100 mg/m(2) × 7 days), combined with either idarubicin (IDR) (10-12 mg/m(2) × 3 days) or daunorubicin (DNR) (50 mg/m(2) × 3-5 days), and then GO (3-5 mg/m(2) ), which was administered 1 day after the last infusion of IDR (IAG regimen) or DNR (DAG regimen). While doses of both GO and IDR and the administration period of only DNR were increased, the dose-limiting toxicity (DLT) was assessed. Among 19 patients (nine in the IAG regimen, 10 in the DAG regimen), the median age was 59 years (range 33-64), and the relapsed/refractory ratio was 13/6. In the therapy using 3 mg/m(2) GO in the IAG or DAG regimen, grade 3/4 leukopenia and neutropenia were observed in all patients, but none had grade 3/4 non-hematological toxicities, except febrile neutropenia. Three patients in the IAG regimen who were administered 5 mg/m(2) GO showed DLT. No patients had veno-occlusive disease or sinusoidal obstructive syndrome. In conclusion, 3 mg/m(2) GO combined with Ara-C and IDR or DNR can be safely administered, and phase II trials should be conducted to investigate the clinical efficacy of the combination therapy.

[Analyses of 6 misidentifications in blood sampling in our hospital].

The initial step of blood transfusion therapy is blood type grouping. ABO-mismatch blood transfusion results in serious adverse effects. 6 incidents in the process of blood type identification, which were caused by misidentification in blood sampling, have experienced in our hospital since October, 2006 to September 2009. We retrospectively examined these incidents, and discussed the reasons and countermeasures. All of 6 incidents were caused by busy residents or nurses during busy hours such as early in the morning or in the emergency. To prevent these incidents, staffs of transfusion unit announced what we have to take care in sampling blood and tied alert tags to sampling tubes. Moreover, we have recently introduced crosschecking computer systems between patients and sampling tubes. We should make continuous efforts to establish safer blood transfusion systems.